Battling Taboos and Scientific Challenges of Rectal HIV Transmission

amfAR-FUNDED RESEARCHERS SHARE FINDINGS, SET PRIORITIES

June 10, 2009—Rectal HIV transmission accounts for a significant number of infections among men and women globally—in fact, perhaps surprisingly, more women are exposed to HIV rectally than men, according to amfAR grantee Dr. Carolina Herrera. But social taboos surrounding anal sex and a related lack of research funding have limited scientists’ ability to evaluate its impact or look for ways to prevent it.

In an effort to address this discrepancy, amfAR awarded grants in early 2007 to eight researchers exploring biomedical and social/behavioral aspects of rectal HIV transmission. The Foundation also supported some related projects outside of this grant cycle. In March, with support from the Calamus Foundation, amfAR brought the researchers to the Massachusetts Institute of Technology’s Endicott House to share their research findings, identify gaps in current knowledge, and establish research priorities.

Several of the grantees focused on developing rectal microbicides to prevent HIV transmission—an area of study that has been traditionally underfunded compared with the search for a vaginal microbicide. “Anal intercourse is the most efficient route of sexual transmission of HIV,” said Dr. Herrera of St. George’s University of London, explaining the urgent need for rectal microbicides.

Noting a lack of support from traditional funders for this area of research, Dr. Charlene Dezzutti of Magee-Womens Research Institute and Foundation in Pittsburgh said that amfAR’s grant was crucial in helping her develop a colorectal explant model to study HIV transmission and microbicides. Another grantee, Dr. Alex Carballo-Dieguez of the New York State Psychiatric Institute and Columbia University, developed a prototype of an applicator to be used with rectal microbicides, and is moving on to conduct further studies funded by the NIH.

The complexities of obtaining accurate data on the prevalence of rectal transmission were noted by several researchers. “I think there’s a mixed reaction to studying heterosexual anal intercourse in South Africa and in Southern Africa in general,” explained Dr. Joanne Mantell of the New York State Psychiatric Institute and Columbia University, who conducted a survey of anal sex practices among high-risk men and women in South Africa. “People do not feel comfortable talking about it, it’s highly stigmatized, and it’s a cultural taboo.” But she emphasized that such studies are critical in order to determine the extent to which rectal transmission contributes to the spread of the epidemic in South Africa.

Southern Californians share a similar reticence on anal sex practices, according to Dr. Marjan Javanbakht of the University of California, Los Angeles, who has studied anal intercourse, sexually transmitted infections (STIs), and HIV among clients at an STI clinic. “People are reluctant to discuss some of their behaviors, even in terms of their clinical care,” she reported.

Many of the researchers expressed their hope that they would be able to use their amfAR-funded work as a starting point for further research into rectal HIV transmission. amfAR’s vice president of research, Dr. Rowena Johnston, who facilitated the conference, explained the importance of providing support for these scientists, particularly in an area that is so critical to HIV prevention and treatment and yet remains understudied.

“We can put a relatively small amount of money into a new research field and demonstrate that there are interesting findings to be made,” she said. “I really hope that what we have done here can be used to inspire other funders to get on board.”